Device for acting on piles, tubing, sheet-piling and the like



Nov. 2, 1965 J. DESVAUX ETAL 3, 09

DEVICE FOR ACTING 0N FILES, TUBING, SHEET-FILING AND THE LIKE Filed Nov.20, 1961 5 Sheets-Sheet 1 him rm L/ncauis Dis/44m Nov. 2, 1965 J.DESVAUX ETAL. 3,215,209

DEVICE FOR ACTING 0N FILES, TUBING, SHEET-FILING AND THE LIKE Filed Nov.20. 1961 5 Sheets-Sheet 2 BY K m/ 11M,

Nov. 2, 1965 J. DESVAUX ETAL 3,215,209

DEVICE FOR ACTING 0N PILES, TUBING, SHEET-FILING AND THE LIKE Filed NOV.20, 1961 5 Sheets-Sheet 3 a m m m A o M w J Nov. 2, 1965 J. DESVAUX ETAL3,215,209

DEVICE FOR ACTING "on PILEs, TUBING, SHEET-FILING AND THE LIKE FiledNov. 20. 1961 5 Sheets-Sheet 4 wrflmeu A90 1 0:: .Dis max Evy/yaw Nov.2, 1965 J. DESVAUX ETAL 3,215,209

DEVICE FOR ACTING 0N PILE'S, TUBING, SHEET-FILING AND THE LIKE FiledNOV. 20, 1961 5 Sheets-Sheet 5 Amen rm United States Patent 3,215,209DEVICE FOR ACTING 0N PILES, TUBING,

SHEET-FILING AND THE LIKE Jacques Desvaux, 17 Ave. du Colonel Bonnet,Paris, France, and Francois Berthet, 16 Rue Voltaire, Houilles, FranceFiled Nov. 20, 1961, Ser. No. 153,504 Claims priority, applicationFrance, Dec. 9, 1960, 846,425 1 Claim. (Cl. 173-49) The presentinvention relates to the driving and extraction of piles, sheet-piling,tubing and the like, and more especially to the technique known asself-driving, which consists in effecting the driving or extraction bymeans of anirnpulse device mounted directly on the pile or the like,without external Support.

In the U.S. Patents Nos. 2,942,427 and 3,008,528, there has beendescribed a driving device of the kind referred to, in which theimpulses obtained by means of an appropriate generator are converted tounidirectional percussions. These percussions are supplied in particularby means of eccentrically-weighted fly-wheels, and more precisely by thevertical or longitudinal component of the centrifugal force offly-wheels rotating in synchronism, the other components balancing outin the horizontal or transverse direction.

Patent No. 3,008,528 has proposed the addition to the generator ofalternating percussions of an elastic means such as a spring for thedamping and the recuperation of the upward percussion for driving or thedownward percussion for extraction, this spring-being placed between thepercussion generator and the frame which is rigidly fixed to the pile.

In this way, devices have been constructed which ensure the driving ofpiles or the like and also their extraction, under good conditions ofrapidity and effectiveness.

However, in certain cases for example, if the ground in which the pileis to be driven is or becomes too hard, or alternatively if the groundhas too little resistance through the first fewmeters from the surface,or again in ground having very low lateral friction, it has beenobserved that the driving device had sometimes a tendency to risebetween the percussions at the stage of upward movement of theimpulse-generator fly-wheels.

This rising tendency which results in a slight upward movement of thepile between the working percussions, is undesirable. It eliminates orreduces contact of the point of the pile with the ground at the momentof the following percussion, which adversely affects the effectivenessand the efficiency of this latter percussion.

The present invention has for its object to obviate this disadvantage,while at the same time offering various advantages of application of thedriving device.

It consists in providing the pile-driving or extraction device (forpiles, sheet-piling, tubing or the like) with means which counteract,reduce or annul the effect of the forces directed in the sense oppositeto that of the working percussions. In the case of vertical drivingpercussions, it .is the forces directed vertically upwards which arereduced or annulled; if the percussions are upward for extraction, it isthe downwardly-directed forces which are counteracted. In the case wherethe percussions are directed obliquely or even horizontally, it is theoblique or horizontal longitudinal forces which are compensated.

A method of counteracting the forces acting in opposition to thepercussions consists in providing the driving device with asupplementary elastic member, such as a spring, arranged between thepile or a frame fast with the pile and the impulse generator, in thezone and on the side where the working percussions are produced.

3,215,209 Patented Nov. 2, 1965 This supplementary elastic member actsin the direction opposite to that of the elastic damping andrecuperation device for the upward impulses. It creates a downwardaction in opposition to the rising tendency. This action maintainscontact of the working point of the pile with the ground at the bottomof the hole, and ensures that the percussions have their full effect.This supplementary elastic means has the further advantage of permittingthe frequency of the percussions to be increased.

Another means of counteracting the forces acting in opposition to theworking percussions consists in generat ing these percussions by meansof several pairs of eccentrically-weighted fly-wheels balanced andsynchronized in each pair, the pairs of fiy-wheels rotating at differentspeeds which are multiples of each other. In its most simple form, thismeans consists in utilizing two pairs of eccentrically-weightedfly-wheels, one of which rotates at twice the speed of the other. Inthis way, stronger impulses are obtained in one direction than in theother and in consequence, in the case of driving there is a predominanceof the downward percussions over the upward forces and vice-versa in thecase of extraction.

The two means previously defined can be put into use in combination,since their effects are advantageously additive both for the eliminationof the undesirable lifting of the pile and for the increase of thefrequency of the percussions and its adaptation to the nature of theground being driven.

In particular, various arrangements, known or novel, of pairs offly-wheels rotating at the same or different speeds may be provided.Thus, the pairs of fly-wheels may be disposed in the moving generator ofthe-driving device. It is however also possible, on condition that theyare associated by an appropriate transmission, to place them partly onthe moving generator and partly on the frame of the device. Or againthey maybe mounted on separate moving generators which are suitablyassociated.

According to the invention, the device carrying into effect theforegoing arrangements comprises, as has already been explained, agenerator of alternating impulses with the conversion of the impulses topercussions in one direction only.

The means employed for obtaining this conversion ensure, as has alreadybeen stated above, the production of a percussion force which is muchgreater than the force of the alternating impulses themselves before thesaid conversion.

Under these conditions, and if the motors which produce the alternatingimpulses are arranged in the generator itself and are rigidly fixedthereto, one of the faces of the generator being used to strike the pileor the frame which is rigidly fixed to it, the said motors are subjectedby the percussion to considerable jerks or shocks resulting inparticular from the setting-up of high-frequency vibrations at thatmoment in the pile and in the driving or extraction device which isrigidly fixed to it.

This is especially the case with the generator havingeccentrically-weighted fly-wheels driven by hydraulic motors placed on'these fly-wheels in the body of the striking mass itself.

These jerks or shocks would be liable to damage these motors veryrapidly. In this way, some motors have been put out of service after afew minutes of working of the devices in question.

According to the invention, there is then interposed between the portionof the generator which strikes the pile and that which comprises themotors, a dampingdevice, the characteristics of which, for example thethickness and the deformation in the case of a simple shockabsorber ofrubber, are such that there is absorption of the high-frequency and highintensity oscillations or vibrations, without however any counteractionor even reduction of the transmission of the forces or blows atrelatively-low frequency due to the percussions produced by the impulsegenerator.

The particular features and other advantages of the invention will bemore fully described with reference to the accompanying drawings whichshow various forms -of embodiment, in comparison with the priorarrangement of which they are improvements.

FIG. 1 shows a view in elevation of the known arrangement.

FIG. 2 is a view in elevation of an arrangement in accordance with theinvention.

FIG. 3 is an explanatory diagram of FIG. 2. FIG. 4 shows a further formof embodiment of the invention.

FIG. 5 is an explanatory diagram relating to FIG. 4.

FIGS. 6 and 7 relate to further forms of embodiment.

FIG. 8 is an explanatory diagram in connection with FIG. 7.

FIG. 9 shows examples of construction of the shockabsorber member whichabsorbs the parasitic oscillations or vibrations.

FIG. 10 is an explanatory diagram relative to FIG. 9.

FIG. 11 shows an alternative form of the shock-absorber.

In FIG. 1, there is shown a driving and extraction device in accordancewith Patent No. 3,008,528, arranged for driving sheet-piling. Thisdevice comprises a frame 10, the lower portion 11 of which is arrangedso as to engage the top of the upper portion of the sheetpiling 12. Thepiling 12 is gripped in the portion 11 by means of any appropriateclamping device 13, mechanical, pneumatic, hydraulic or other.

The impulse generator 14 is slidably mounted in the interior of theframe 10. This generator is for example of the type with two fly-wheels15 having eccentric weights 16, rotating in opposite directions andsynchronized. This generator is arranged so as to produce percussionswhich are transmitted by the hammer 17 to an anvil 18 carried by thelower portion 11 of the frame 10 and to the sheet-piling 12.

It should be observed that the assembly of the generator and its frameis mounted on the sheet piling 12 without any external support,following the technique known as self-driving referred to in Patent No.2,942,- 427.

The generator 14 as shown in this case produces alternating impulses. Itis preferably arranged so as to convert these impulses intounidirectional percussions, for example following the arrangementdescribed in Patent No. 2,942,427.

In accordance with the provisions of Patent No. 3,008,528, one or anumber of elastic elements, for example the springs 19, are interposedbetween the impulse generator 14 and the upper portion 20 of the frame10. The tension of the spring or springs is regulated by means of jacks21, it being possible to carry out this adjustment while working. Thespring or springs19 have the efiect of storing the energy developed bythe impulse generator 14 during its upward travel and restoring theenergy on the downward travel, thus increasing the effect of percussionson the anvil 18 and on the sheet-piling 12. In addition, the spring orsprings 19 permit the frequency of the oscillations of the generator 14to be increased.

It will be recalled that for the extraction of the sheetpiling, theposition of the spring or springs 19 is reversed, that is to say thisspring is interposed between the generator 14 and the lower portion 11of the frame,

working in the reverse sense, increasing the effect of the upwardpercussion.

With this device it has been found in certain cases, depending on thenature of the ground in which the driving of the sheet-piling iseffected, that there is a slight tendency of the sheet-piling to lift,or at least there is a movement of its working point away from thebottom of the hole during the phase of upward movement of the eccentricweights 16. The assembly comprising the generator 14 and frame 11 isthen liable to function as a vibrator, and the device loses itsetfectiveness and exhibits a tendency to galloping.

The improvements according to the invention have the object ofcounteracting these effects by opposing, in the case of driving, thelifting effect with eventually a differential action of the alternatingimpulses, made predominant in the direction of the downward workingpercussions.

To this end, a first means consists, as shown in FIG. 2, in providing,in addition to the springs 19, between the generator and the upperportion 20 of the frame 10, a set of springs 22 between the generator 14and the lower portion 11 of the frame 10.

With this arrangement, when the generator 14 is stopped, it is inequilibrium between the springs 19 and 22. These springs are calculatedand arranged in such manner as to form in the stopped position as shown,a space 23 between the hammer 17 and the anvil 18. This space isdetermined in such manner that the beating of the hammer 17 on the anvil18 takes place starting from a pre-determined speed of operation of thegenerator 14.

When the generator 14 is working, during the downward travel, thesprings 19 play their usual part of restoration of energy, reinforcingthe elfect of the percussion. At the same time however, the springs 22are compressed, applying a downward thrust on the portion 11 and thesheet-piling, forcing the piling in the direction of driving.

During the upward movement of the generator 14, while theupwardly-directed impulse compresses the springs 19, the springs 22expand and react on 11 to apply a downward action on the sheet-piling12, thus maintaining it in the driving direction.

By means of the springs 22, it is also possible to-increase thefrequency of the percussions to a greater degree than would be possibleby the action of the springs 19 alone. If the springs have an increasingcompression gradient, the oscillation frequency of the generator 14increases as a function of the increase in compression of the springs 19and 22.

The assembly comprised by the generator 14 and the springs 19 can becompared to a pendulum A (FIG. 3), oscillating between two springs B andC. It is known that the frequency of oscillation of the pendulum A thusarranged increases in proportion to the increase of the compressiongradient of the springs B and C. The double set of springs 19 and 22(FIG. 2), similar to the springs B and C of FIG. 3, ensure a greaterincrease in frequency.

By the double action of the springs 19 and 22, the operation of thedriving device is thus improved. More regular percussions are obtained,irrespective of the depths reached and the nature of the groundencountered. All parasitic effects are avoided, in particular thejumping back of the sheet-piling. f

FIG. 2 and the foregoing explanations relate to the driving of thesheet-piling 12. It will be understood that for the extraction of thepiling, the actions are reversed. In particular, the hammer 17 and theanvil 18 are then placed above the generator 14, and the springs 19 and22 are interchanged in position.

A further means, which can be employed with that of the precedingembodiment of FIG. 2, but which can also be applied independently of theprevious method, consists in equipping the driving device with animpulse generator comprising a number of sets of fly-wheels synchronizedin each set, rotating at different speeds and supplying for that reasondifferentiated vertical actions, upwards and downwards.

An arrangement of this kind is shown in FIG. 4. The impulse generator14a movably mounted on frame 10a comprises two sets of superposedfly-wheels 24 and 25. In each set, the fly-wheels are synchronized. Oneof the sets of fly-wheels, 24 for'example, rotates faster than the otherset 25. These fly-wheels carry eccentric weights 26 and 27 respectively,having. appropriate masses and positions, in particular being soarranged that they coincide in the bottom positions when the eccentricWeights 27 .of the slower fly-wheels 25 reach the lower position. Thefly-wheels 24 and 25 are associated by an appropriate transmission 36comprising a rotating shaft having a bevel gearing at its ends.

By this means, a more powerful action is obtained in the downwarddirection than in the upward direction, as explained by the diagramofFIG. 5. In this diagram, it has been assumed that the fiy wheels 24are rotated twice as fast as the fiy-wheels 25. During the course of acycle of rotation ofthe slowerfly-wheels 25, the assembly' passesthrough successive phases I, II, III, IV, V, the latter phase beingidentical with phase I and recommencing the cycle.

If F is the resultant of the vertical forces due to the fly-wheels 24and f is the resultant of the vertical forces due to the fly-wheels 25,it can be seen that this resultant reaches F+f in the downwarddirection, but remains limited to F in the upward direction.

By a suitable choice of the masses of the weights 26 and 27, it is aneasy matter to obtain f=F. The force is thus doubled in the drivingdirection without affecting the force in the upward direction. Thisresults in an improvement of the effectiveness of the device.

According to a further form of embodiment shown in FIG. 6, in additionto the generator 14b with its flywheels 15b and eccentric weights 16b,the device comprises a second set of fly-wheels 28 with eccentricweights 29, this being mounted on the frame b. This second set offly-wheels 28 is synchronized with the fly-wheels b by a conventionalsliding or telescopic transmission 30 having bevel gearing at its endsand a splined connection intermediate its length by which the twosections of transmission 30 are enabled to have axial sliding movementrelative to each other. However, the directions of rotation of thefly-wheels 28 are reversed wit-h respect to those of the fly-wheels 15b.

When the generator 14b moves upwards after -a percussion, it may have atendency to lift the sheet-piling 12 by compressing the spring 19. Thefly-wheels 28 oppose this tendency by pushing the sheet-piling 12downwards. The two effects annul each other. At the following halfperiod, the fly-wheels 29 will tend to lift the pile at the moment whenthe percussion of the generator 14b drives it. As the effect ofpercussion is considerably greater than the effect of the fly-wheels 28,the lifting tendency of the fly-wheels 28 has no effect.

FIG. 7 shows a further arrangement with two sets of fly-wheels rotatingin opposite directions. In this arrangement, one of the sets offly-wheels 15c is carried by the generator 140 as in the previous case.But the generator 14c, sliding in the frame 100, carries itself a frame31 with slides, on which moves a further impulse generator 32 carryingthe fly-Wheels 33 with eccentric weights 34. The fly-wheels 33 aresynchronized with the flywheels 150 by a conventional sliding ortelescopic transmission 35 similar to transmission 30 described above.

The fly wheels 33 and 15c rotate in opposite directions. The springs 19and 22 of the previous examples are placed in this case on each side ofthe generator 32.

In this arrangement, the vertical component at every instant due to thegenerator 32 acts in opposition to that produced by the generator 14c.Any tendency of the sheet-piling to lift is thus eliminated, since noreaction of the generators is transmitted to it, with the exception ofthe percussion which takes place during one of the phases of themovement of the said generator 140.

In another phase of movement of the generator 14c, the latter tends torise and its upward movement is counteracted by the effect of thegenerator 32, which has 6 the result of accelerating the movement of thegenerator downwards. This acceleration depends on the characteristics ofthe springs. At the moment of the percussion, the generator 32 obviouslytends to lift the generator 140, but this tendency to lift, acting in adirection contrary to driving, has no effect since the force of thepercussion blow is from 10 to 12 times greater than that of thecentrifugal force developed by the generator 32, when the impulsesproduced by the generatorhave suit-: able lengths and frequencies.

This assembly is comparable. in a way, with two syn-. chronous pendulumsD and E (FIG. 8) coupled together by a spring G. The frequencies ofoscillation of this unit depend on the compression gradient of thespring G. The conditions of operation thus depend on the characteristicsof the springs 19 and 22, which should be springs with a variablegradient.

In FIG. 9, there has been shown one of the possible arrangements of theshock-absorber placed, according to the invention, between the motor ormotors 37 of the impulse generator and the portion of this generatorwhich strikes the pile or the frame which is rigidly fixed thereto.

For the sake of clearness of the drawings and with the object ofsimplification, this shock-absorber has been shown applied to a deviceof the type illustrated in FIG. 1 above; it will however be obvious thatit may be utilized with any one of the arrangements previouslydescribed.

In FIG. 9 can be seen the shock-absorber 38, which may be a suitable padof rubber placed between the face 39 of the generator and the hammer 17dwhich also forms part of the said generator. In the arrangementconsidered here by way of example, the springs 19d are deformablemetal-rubber elements stacked one on the other.

The pad 38 is of sufiicient thickness or has the requiredcharacteristics to intercept or deaden the high-frequency vibrations andabnormally-high shocks, Nevertheless, it should not flatten too much soas to avoid troublesome work and heating, and also to avoid damping ofthe shocks or percussions to be transmitted to the member which is beingdriven or extracted.

To this end, as shown in the diagram of FIG. 10, the rubbershock-absorber 38 is not only placed between the face 39 of thegenerator and the hammer 17d, but is also surrounded by the profile 40of a part which is rigidly fixed to a part 39 or 17d of the assembly 39and 17d. It is already in abutment against this profile 40 when themachine is stopped, as a result of the mechanical load and when sorequired, of a slight pre-stress. During the course of operation, itsdeformation 41-42 is controlled, the volume of expansion diminishing asthe impulses or shocks increase, which are transmitted to the member tobe driven or extracted.

A further arrangement in accordance with the invention is shown in FIG.11. In this figure, the impulse generator with fiy-wheels 15e andeccentric Weights 16e comprises motors 37 fixed to the driving casingsof the flywheels. An assembly comprising the guiding rods 1012(replacing the frame 10 of the previous figures), the cross-beam 20arigidly fixed to this rod, the lower portion He also serving as theanvil 18e is fixed to the sheetpiling 12 to be driven. A hammer or ram17e, which is rigidly fixed to the generator 142 by means of a pneumaticor hydraulic belt 38e, replaces the pad 38 of FIG. 9. The said belthaving limited and controlled deformations is remarkably effective andensures the possibility of arranging the motors in the impulsegenerator, even if there is not provided between them and this generatoran elastic coupling of any kind such as has always been proposed up tothe present time.

It will be understood that the arrangements which have been describedabove have no limitative nature and may comprise all the alternativeforms of construction, without thereby departing from the scope of thepresent invention.

What We claim is:

A device for acting on piles, tubing, sheet-piling and the like, bothfor their driving :and their extraction, comprising a frame adapted tobe rigidly fixed to the pile, said frame including a base plate forengaging the pile, guiding means parallel to the axis of the pile, across member coupling said guiding means together at their extremities,an impulse generator mounted on said frame and adapted to be guided bysaid guiding means, spring means arranged between said cross member andthe generator for converting the alternating impulses to unidirectionalpercussions, and additional spring means arranged between said baseplate and the impulse generator opposite to said first-mentioned springmeans which convert the alternating impulses to unidirectionalpercussions, said first-mentioned spring means and said additionalspring means having a variable compression gradient, the

degree of compression of said spring means acting to vary the frequencyof the percussions.

References Cited by the Examiner UNITED STATES PATENTS 1,280,269 10/18Miller 7461 2,102,603 12/37 Pinazza 173-49 2,545,245 3/51 Stutz 175552,990,022 6/61 Muller et a1. 17555 3,008,528 11/61 Berthet et al 175-55FOREIGN PATENTS 1,131,102 2/57 France.

MILTON KAUFMAN, Primary Examiner.

BROUGHTON G. DURHAM, CHARLES E. OCON- NELL, Examiners.

